The need for significant increases in the Defense budget has now become widely accepted. Such increases are necessary to make up for the spending that was deferred -- for manpower, readiness and procurement -- both during and after Vietnam. What is not so well understood is that the degree of our self-deception has been so great -- as inflation has decimated a Defense budget allegedly enjoying substantial "real growth" -- that the backlog of even routine expenditures is staggering. (The unrealistic inflation-rate assumptions imposed on Defense by the White House and the Office of Management and Budget remind you of hearing a weather forecast saying "40 percent chance of snow tonight" while you are watching a blizzard through the window.)

Working off this backlog of routine but vital items is essential to keep our military services from being "hollow," as the chief of staff of the Army recently labeled some of his divisions. New capabilities -- more aircraft carriers or Army divisions, for example -- may be desirable, but we ought to fix the leaks in Defense's roof and replace the rotting timbers before we begin adding pretty new rooms to the house.

For starters, former secretary of defense Melvin Laird puts the military pay backlog at $5 billion, caused by various recalculations and pay caps that have held military pay well below the inflation rate. And, after making up for that backlog, maintaining annually the higher pay, family housing construction and other personnel spending -- such as a new GI Bill -- necessary to give the All-Volunteer Force even a slim chance will mean another several billion each year above what we have become used to.

Military readiness has been the constant post-Vietnam victim of budgeteers in all parts of the government. Congress, for example, cut the Defense budget requested by the president every year for 15 years until the increase last year. In many of these years it also added big-ticket weapon systems. That meant that it had to make even greater compensating cuts somewhere -- often in readiness. As a result, according to American Enterprise Institute figures, our Air Force pilots have been given only enough fuel to fly about 10 hours a month. Israeli pilots, by comparison, fly 30. AEI points out that the backlog in ammunition and tactical missiles, for example, both for training and war reserves, is awesome. Anti-tank gunners fire one missile per year in training; some pilots fire an air-to-air missile only once in their career. The Air Force has about two weeks of ordnance on hand for air-to-air combat; the Navy, about two plane-loadings' worth.

If you're a pilot, what do you do during the period after, say, two weeks of combat when you're out of ammunition and before the time -- many months later -- when the factories are finally producing ordnance and it gets across the ocean to you? That's not clear; but whatever you do, you'll do it very carefully. Estimates vary, but increasing ordnance stockpiles to a mere 30-to-45 days' worth from their dreadfully low states would mean a one-time cost on the order of $20 billion to $30 billion. As in the case of manpower, buying adequate levels annually -- of fuel and ammunition for training, for example -- would then cost several billion dollars, on a continuing basis, above what has become customary.

Putting the cost of significantly reducing these manpower and readiness backlogs together with the needs stemming from very low current weapon procurement rates gives the dimension of the problem. Much strategic and Navy ship procurement, for example, was deferred during Vietnam in order to fund the war, and thus strategic forces and the Navy need more for modernization now than if they had been modernized a decade ago. Aircraft, key classes of ships, tanks and the like -- almost across the board -- are now being bought at rates from a half to a fifth those that would be needed just to replace obsolete weapons and the accident losses that relentlessly reduce the existing level of forces.

Matching the Soviets would, in most cases, take even more than that. For example, you need approximately to treble or quadruple the rate of general-purpose submarine construction in the Carter administration budget just to maintain our existing submarine force (which is about 40 percent the size of the Soviets'); you would need to increase the Carter rate 10 times to match today's Soviet building rates.

In time, innovation in weapons and design and tactics will affect the nature, and possibly reduce the cost of, these weapons purchases -- e.g., if we move toward smaller, lighter, more maneuverable tanks. But we need to step up what we now have in production -- just to hold the armed forces together -- while simultaneously pushing such reforms. We can't permit ourselves another several years of fooling around and not even replacing the small number of naval aircraft we lose in accidents annually while we keep arguing the big-versus-little issue on each type of weapon.

Because of inflation, the broad proposed cuts in domestic spending and all this deferred spending on basics for the military, the Reagan administration will face a major squeeze in its early decisions this month about amendments to Carter's defense program. There will be pressure to hold down the increases and to spend whatever can be afforded on something flashy. But the Vietnam and post-vietnam backlogs on the basic needs of our existing forces are going to be virtually impossible to work off -- even over several years -- without moving the Defense budget up, in that time, to a level at least 1 percent of GNP above today's: a $25 billion to $30 billion annual increase.

That is a lot of money, but it is only one-eighth of the proportional jump in Defense spending we had at the beginning of the Korean War (i.e., up 8 percent of GNP in two years) and would still leave us at only about three-fourths the proportionate commitment to Defense we supported as a nation during the Kennedy administration. The current popular enthusiasm for increasing Defense capability may not last, especially when people begin to feel the domestic spending cuts. While it does last, we should take care of the basics. Otherwise, we may see hollow new units added to hollow old units. That would not only be a mistake, but would mark a new round of self-delusion.